Ms Craddock said she feels "hugely excited" and "very privileged to be involved with this".

"There are moments where I've focused on it being another commission, so it's like working with any one of our couples, and of course you take a step back and you just realise the enormity of it," she said.

"It's a huge occasion and we're just hugely privileged."

She was joined on a tour of the Windsor Great Park by John Anderson, keeper of the gardens, whose team will be sourcing the foliage for the florist on the big day.

Ms Craddock said: "The base is the foliage, that's where the designs start from and then the flowers are complementary on top of that, but actually it's very much the foliage and shapes of the branches that will give us the shape of the designs.

"One of the things that has been very important in this brief to me is to make sure we're sourcing locally and that the designs reflect the landscape that's around Windsor Castle, that's what we're looking to do in the chapel.

"For me, as when I work with all couples, it's been a highly collaborative process so everybody's been involved and everybody's had actually coincidentally similar ideas."

Despite Mr Anderson's involvement in the big day, he said he doesn't know how the arrangements will look, and will see them in the chapel on television along with other people watching, for the first time.

Speaking about the birch, he said: "It's a native tree and in the forestry they self seed everywhere so you could say they're a bit of a weed - a nice weed - this week they're a very special weed that will be used by Philippa and the team."

Ms Craddock said she has a "very, very clear idea" of how everything will look on the day, but her gardener counterpart admitted the recent spate of good weather did mean there had been some last minute tweaks.

Mr Anderson added: "A few days ago it was really hot, some things might not last if you cut them, we've been trialling some of these as well so we've been very efficient about what we're going to cut and how it can be used."

Planning for the wedding began in the winter, and the teams moved some routine jobs to prune the royal wedding trees.

:: Sky News is live in Windsor all this week bringing you all the build up to the big day, with exclusive live coverage of the wedding in UHD in a special programme ‪from 9am to 3pm on Sky News and Sky One ‪on Saturday 19 May.